Absorbent articles such as infant diapers, training pants, adult incontinence products, and the like are well known. Such articles have achieved a wide acceptance due to their ability to receive and absorb body exudates.
This invention pertains to an absorbent article for containing body exudates. This invention utilizes a fecal material retaining structure having at least one, and preferably multiple apertures to receive and retain exudates, and especially fecal material.
In general, body exudates of urine and fecal material should be received and retained by the absorbent article. However, leakage problems are common, especially of liquidous or semi-liquidous fecal material. Furthermore, even if fecal material does not leak, it can have an adverse impact on the skin of the user or wearer of an absorbent article.
Typically, fecal material is received at the surface of the bodyside liner. Mobile liquid contained in the fecal material may be absorbed through the bodyside liner, into an absorbent core of the absorbent article, and thus moved away from the skin of the user. However, in most cases the solids portion of fecal material, along with any liquid which is immobilized in the solids portion, generally remains at the surface of the bodyside liner, incapable of penetrating through the bodyside liner and moving away from the skin of the user. In such cases, the solid portion of the fecal material typically remains trapped at the outside surface of the bodyside liner, between the bodyside liner and the skin of the user. During normal usage the fecal material can spread outwardly along the outside surface of the bodyside liner and cover an increased area of the skin of the user.
Some attempts have been made to remove the fecal material from the skin of the user. For example, one absorbent article includes a single large hole aligned between the buttocks of a user. The single hole opens into a containment chamber to contain and store exudates, and especially fecal material. However, the single large hole is not held or otherwise fixed in its location with respect to the anus of the user.
U.S. Pat. No. 5,342,338 to Roe discloses small apertures in the bodyside liner of an absorbent article to dewater fecal material. However, little if any of the fecal material is displaced from the skin of the user.
In the present invention, an absorbent article displaces fecal material from the skin of the user, and thereby reduces the amount of contact between the fecal material and the skin of the user or wearer of the absorbent article. Absorbent articles of the invention use an apertured retaining structure placed in the rear portion of the absorbent article to control placement of the fecal material. A slick outer surface utilizes the pressure of the body of the user on the retaining structure, in combination with sliding movement between the outer surface and the body of the user, to move fecal material into the apertures and away from the skin. Use of the retaining structure provides easier clean up of the skin of the user after the absorbent article is soiled. Additionally, fecal material is prevented from spreading to the front portion of the absorbent article and contaminating other parts of the body of the user.
In one embodiment, the absorbent article has a length, a front portion, a rear portion, a crotch portion connecting the front and rear portions, and a central axis perpendicular to the length of the absorbent article. The central axis extends across the crotch portion and divides the absorbent article into two sections of approximately equal length. The absorbent article comprises a chassis having an outer cover, and a bodyside liner mounted in facing relationship to the outer cover and contacting the body of the user in the front portion of the absorbent article. The absorbent article includes an absorbent core located between the bodyside liner and the outer cover in the front portion of the absorbent article, and not in the rear portion; and a fecal material retaining structure mounted to the chassis in the rear portion of the absorbent article and contacting the body of the user. Edges of apertures of the fecal material retaining structure are generally in direct contact with the body of the user.
In another embodiment, the fecal material retaining structure comprises at least a first layer of a highly absorbent material such as cellulosic pulp, and at least a second layer of resiliently compressible surge material.
In another embodiment, an outer surface layer forms the outer surface of the fecal retaining structure: The surface layer has a hydrophobic, slick outer surface for contacting the body of the user and facilitating movement of fecal material material into at least one aperture. The surface layer has a critical surface tension for wetting that preferably is less than the critical surface tension for wetting of fecal material from a breast fed infant. The critical surface tension for wetting of the surface layer is typically less than about 50 dynes/centimeter, and preferably is about 30 dynes/centimeter, to assist with moving the fecal material of a breast fed infant into one or more apertures in the fecal material retaining structure.
In other embodiments, the fecal material retaining structure has at least one aperture penetrating the first and second layers of the fecal material retaining structure. The at least one aperture preferably has a volume between about 14 cubic centimeters and about 26 cubic centimeters at rest. The combined uncompressed thickness of first and second layers adjacent at least one aperture is between about 0.5 inch and about 1.0 inch. An at least one large aperture preferably comprises multiple apertures covering between about 40% and about 60% of the surface area of the fecal material retaining structure. A surface area of the fecal material retaining structure is defined as that area bounded by a perimeter within which the fecal material retaining structure contacts the body of the user. The surface area of each of the large apertures in the absorbent article preferably is at least 5 square centimeters.
The apertures can have a tear-drop shape, a circular shape, an elliptical shape, a diamond shape or other shape or shapes. The large tear-drop shaped aperture preferably has a greatest width of about 1.5 inch and a greatest length of about 2 inches.
In some embodiments, a front edge of the fecal material retaining structure extends from about 0.5 inch to about 2 inches frontwardly in the absorbent article beyond the central axis. The width of the fecal material retaining structure can substantially equal the width of the absorbent core in the front portion of the absorbent article.
In some embodiments, a support layer of absorbent material is located between the fecal material retaining structure and the chassis. Fecal material moves through the apertures to contact the support layer. The support layer receives liquid from the fecal material, and preferably swells no more than about 13% upon absorption of body exudates. The support layer preferably comprises a fibrous cellulosic pulp having a basis weight of between about 90 grams per square meter and about 140 grams per square meter. The layer of absorbent material has an absorption capacity ratio of between about 6 grams and about 10 grams of liquid exudates per gram of material.
In another embodiment, at least two apertures extend through at least the first and second layers of the fecal material retaining structure to receive and retain fecal material. The apertures preferably have an overall volume of at least 140 cubic centimeters at rest and are arranged and configured to conform to the body of the user. Larger apertures are preferably sized to retain fecal material having a thickness greater than about 0.5 inch. Smaller apertures provide enhanced flexibility to the fecal material retaining structure.
In some embodiments, at least one first layer of a first material is secured to the surface layer, at least one second layer of a second material is secured to the first layer, and at least two apertures are formed in the surface layer. The first and second layers and the at least two apertures receive and retain fecal material.
In yet another embodiment, the first layer comprises multiple layer elements of the first material and/or the second layer comprises multiple layer elements of the second material, the multiple layer elements being interleaved and respectively secured to one another.